1. Field of the Invention
The present invention relates in general to tip-in casement windows, and more specifically relates to an improved construction for such casement windows to provide a simple yet effective way to greatly increase the insulative capability of such windows.
2. Description of the Prior Art
Tip-in casement windows have been known in the art for many years and numerous types of tip-in casement window constructions are available in the market today. The most common type of casement window construction has an outer frame and an inner sash frame which houses one fixed glass pane unit and one slidable glass pane unit. The outer frame has a continuous inwardly directed retaining flanges which are located on the outer edges of the side and top portions of the frame. The bottom portion of the frame also has an inwardly directed retaining flange, but this flange is located toward the rear edge of the bottom portion. The sash has outwardly directed flanges designed to mate with the appropriate retaining channels of the frame so that the sash may be "tipped-in" into the frame and thereby be secured through retaining clips located at the top of the sash. This common design allows for the simple and easy assembly of such casement windows.
Although the above described common casement window construction has proven to be commercially successful in that it provides an effective means to assemble the sash into the wall frame, such construction does not provide a satisfactory means to insulate and seal the joint between the sash and the outer frame. Typically, the top and side flanges of the sash have a front gasket which provides for an uninterrupted seal for those upper portions of the sash. However, because the bottom flange of the sash is offset from the sash top and side flanges, it is not possible to have an uninterrupted seal completely around the front of the sash. Therefore, this known design does not provide for effective bottom sealing. In contrast to the prior art construction, the present invention includes a bulb-type bottom seal construction to provide an improved tip-in casement window with an increased insulative capability.